1. Field of the Invention
The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device for use in an entertainment machine.
2. Description of Related Art
An example of a conventional rotary entertainment machine using a liquid crystal display device will be described with reference to FIGS. 16 and 17 (see, for example, JP-A-2004-283548). FIG. 16 is a perspective view showing the exterior appearance of a conventional rotary entertainment machine 100, and FIG. 17 is a longitudinal sectional view showing a positional relationship of a rotary display body 102, a liquid crystal panel 116, and a liquid crystal shutter 112. This rotary entertainment machine 100 has a cabinet 101 provided with, at substantially the top center of the front face thereof, three display windows 103a to 103c arranged side by side through which the surfaces of three rotary display bodies 102a to 102c arranged inside the cabinet 101 can be seen respectively.
A game result display portion of this rotary entertainment machine 100 is provided with first display means composed of three rotary display bodies 102a to 102c, second display means composed of the liquid crystal panel 116 placed in front of the first display means, and third display means composed of the liquid crystal shutter 112 placed between the first display means and the second display means. The second display means has a transmissive display portion (not shown), and transmits what is displayed on the first display means and thus making it visible. The third display means has three display blocking portions 113a to 113c that individually block or transmit what is displayed on the first display means.
The entertainment machine 100 further includes switching control means that switches the display blocking portions 113a to 113c between a state in which what is displayed on the first display means is blocked and a state in which what is displayed on the first display means is transmitted.
Inside the rotary display bodies 102a to 102c, three backlights 117a to 117c are arranged for individually illuminating the rotary display body. In front of the rotary display bodies 102a to 102c, front illumination devices 118a and 118b are placed for illuminating the liquid crystal panel 116 and the liquid crystal shutter 112 from behind and for illuminating the rotary display bodies from the front.
The inventors of the present invention manufactured a liquid crystal display device for use in the entertainment machine 100 by referring to FIG. 17. This liquid crystal display device is provided with an outer frame that covers a liquid crystal panel 116 and a liquid crystal shutter 112. The outer frame has an opening portion at one side thereof and is formed as a picture frame-shaped member. In addition to the liquid crystal panel 116 and the liquid crystal shutter 112, there are placed a light guide plate and a fixing plate. The light guide plate, the fixing plate, and the outer frame each have, at the center thereof, an opening portion.
Inside the picture frame-shaped member of the outer frame, a circuit board is placed on the fixing plate with an insulating tape laid in between. Inside the picture frame-shaped member, there is placed a flexible circuit board having one end connected to an edge portion of the liquid crystal panel 116 and the other end connected to an edge portion of the circuit board.
In general, a general-purpose flexible circuit board is so designed as to have a relatively long length so as to be connected to a circuit board fixed to a bottom plate provided behind the liquid crystal panel 116. As a result, in the liquid crystal display device manufactured by the inventors of the present invention, an assembly of this flexible circuit board and the circuit board connected thereto increases in length. This makes larger the width of the picture frame-shaped member accommodating this assembly, undesirably increasing the external dimension (width) of the outer frame.
On the other hand, if the opening portion of the outer frame is made smaller so as not to increase the external dimension of the outer frame, this makes it harder for the user to visually see, through the opening portion, the rotary display bodies 102a to 102c located behind the opening portion.
To overcome the problem described above, the inventors of the present invention studied the use of a shorter flexible circuit board, only to find out that, since it is not a general-purpose flexible circuit board, this inconveniently leads to increased cost.
Incidentally, a clearance of a predetermined distance was created between the liquid crystal panel 116 and the liquid crystal shutter 112. However, the liquid crystal shutter 112 is bent toward the liquid crystal panel 116 and then is brought into contact therewith, undesirably creating moire (interference of light). Through a study in search of the causes, the inventors of the present invention have found out that, since first and second circuit boards constituting the liquid crystal shutter 112 are thin, the liquid crystal shutter 112 is warped (bent) to one side.
To overcome the problem described above, the inventors of the present invention manufactured a liquid crystal shutter by using first and second circuit boards each having the same thickness as that of the circuit board used in the liquid crystal panel 116. This inconveniently leads to increased cost.